How can sections be added to the RAM Structural System tables?

For a detailed explanation of table editing please refer to the RAM Manager manual (RAM Manager - Help - Manual).

In general, the master steel table is a text file that can be edited using any text editor (e.g. Word Pad). To add new sections to the table, just add new lines to the file within the appropriate section of the file (W, TS, etc.). Section names should not include any spaces, they should be unique and no more than 15 characters long. 

If you prefer to use the program's built-in table editor, you can access this from the RAM Manager Tools menu.

If the added sections are to be used in steel beam design, then you must also add those section names in the steel beam design table (e.g. RAMAISC.BMS) followed by a space and then a "+" sign. The meaning of this and other symbols is discussed in the RAM Manager manual under Beam Design Table. Place the new section in the list of beam section between the next lighter and heavier sections (i.e. sorted by weight).

It is always recommended to use a new file name, rather than editing the original master and design beam tables because the original tables are reinstalled with each new version of the software.

Also note, the steel tables used in the RAM SBeam program are in the same format. Appendix A from the RAM SBeam manual can be read here: Appendix_A_RAM_SBeam_Tables

I added a custom table, but it's not available for me to select in the Ram Manager Criteria, or in the Steel Beam Connection Check.

Make sure the table has the right extension. Some editors insist on appending an extra .txt on to the end of the file name when saving. So you end up with something like Mybeams.bms.txt rather than just MyBeams.bms, and that causes the files not to have the right extension so they are filtered out. Removing the trailing .txt extension may require some changes to the windows file browser default folder options as shown below:

The most reliable approach is to copy one of the files provided with the installation, then edit the contents of that new file and save using Notepad or Notepad++.

Also, make sure the file is placed into the correct folder locations. The default location for Tables in Windows 7 is:

 C:\ProgramData\Bentley\Engineering\RAM Structural System\Tables

But this can be confirmed by opening RAM Manager - Criteria - Master steel table and looking at the top.

Note, the path to the Tables directory can be modified by editing the ramis.ini file as indicated on the RAMSS Files [FAQ] or by reinstalling the software and changing the directories.

If the file is listed, but gives an error like "Improper Units on line 1" it might be that the custom table is not a plain ANSI text file, but a text file with formatting.

Be sure to save the files as "plain Text" or with ANSI encoding only.

Why do I get a cryptic error message looking up a section in the Master Steel Table when I use my custom beam table?

If the custom beam table is not a plain text file and includes any formatting which might come from using a rich text editor, then you can get a cryptic message like the one below when running the beam design.

Copy the text to a new plain text file as outlined above to solve such a problem.

Can a bottom flange plate be added to a beam and checked as a composite section?

When using built-up shapes as composite sections the new built up shape will need to be added to the master table and steel beam design table. When using built-up members, note the following:

All of the calculations of the composite section are still based on an assumption that the shape is an I-shaped section, all of the equations used by the program for wide-flange beams were derived from that shape. If the plastic neutral axis falls down in the bottom flange or within the added shape, the results given by the program will potentially be wrong (except for the case of a plate).

When the reinforcement is a plate, it is straight-forward: specify the bottom flange with a thickness of the combined flange and plate (tf' = tf + plate thickness) and specify the width as the width that would produce the same area as the combined flange and plate (bf' = (area of flange + area of plate) / tf'). This will give correct results, except the check for width / thickness requirements of the bottom flange will be based on the tf' and bf' dimensions rather than the real dimensions (which shouldn't be a problem unless the plate is very wide and thin). In this case Note, you do not have to specify the values of Area, Ix, Sx, Zx, etc. in the table(i.e., only specify the top and bottom flange dimensions and the depth and web thickness). If those values are left blank the program will calculate them based on the rectangular section dimensions.

Reinforcing the section with something other than a plate is more complicated. The dimensions specified for the bottom flange would have to account for the contribution of the real configuration of flange and channel or tube. You can't do this so that both the Zx (plastic section) and Ix (elastic section) are correct if the PNA or Ybar for any of the conditions (pre-composite or composite) falls in the bottom flange or in the added shape. I would try the following: calculate the bottom flange thickness as the overall vertical dimension of the flange thickness + the vertical dimension of the added shape (e.g., tf' = tf + tw for a channel, tf' = tf + b for a tube). Then calculate the area of the bottom flange + the area of the added shape. Then calculate the "equivalent" flange width (bf' = (area of flange + area of added shape) / tf'). Note that this is identical to what was done in the previous paragraph for a plate, but especially in the case of an added tube these dimensions will look very odd (thick and narrow). Again, do not specify the Area, Ix, etc in the table; let the program do that. Again, as long as the PNA is not in the bottom flange, the program should calculate Z correctly. I think that the deflections will also be correct as long as the elastic neutral axis (Ybar) does not fall within the bottom flange or added shape. Note that one major problem is that the program will not correctly perform any of the b/t checks for the added shape (for example the b/t ratio of the tube web) or for the bottom flange. If any of the elements are slender the composite design would be invalid.

How can I get column trial groups deeper than W14's?

To activate larger depth trial groups, edit the column design table (or use the ramasic2.col table which includes all the AISC shapes). You'll find details in the Ram Manager manual, look for the section titled, "Column Design Tables". 

See Also

Product TechNotes and FAQs

Structural Product TechNotes And FAQs

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Comments or Corrections?

Bentley's Technical Support Group requests that you please confine any comments you have on this Wiki entry to this "Comments or Corrections?" section. THANK YOU!

How many training hours -As in Learn Server- Would it take me to master Steel Design in STAAD.Pro, assuming that all fundamental courses were taken?

Document Information

Document Type: TechNote  

Product(s):  SELECTservices

Version(s):  All

Original Author: Bentley Technical Support Group

Legacy Document Number: 7115

Overview

Bentley offers full versions for products on MySELECT CD , Bentley's software download and mailing service. Recently this site has been updated as the Software Fulfillment site, but the images and instructions here pertain to the older site, also known as "Web Downloads".  

A Bentley login is required to obtain this software. Your login information should have been sent to you from Bentley Support with your order. If your login information is not readily available, try using the following guidelines. The user name is generally set to the email address of the individual who set up the contract with Bentley. If you do not remember your password, please use the Forgot Password link with your login e-mail address, or go to https://ims.bentley.com/IMS/Account/PasswordReset?wtrealm=loginnet.bentley.com to reset your password. Please contact Bentley Support at 1-800-BENTLEY or submit a service ticket online at http://appsnet.bentley.com/srmanager/addcall.aspx if you need your login information.

The link above may take you to a login screen like the one pictured in Figure 1. If a long form appears instead, locate a box just above it that reads "Already have a login? Click here." Click the "here" link to proceed to the Bentley Login screen.

Figure 1: Bentley Login screen

Once logged in, the screen featured in Figure 2 will appear.
Important: If you see a non-SELECT user message, please contact Bentley Support for further assistance.

Locate the Search By section, and select your product line from the first drop-down menu (circled in Figure 2), depending on the products you need. For example, choose "RAM Products" if you need RAM Structural System. By default MySELECT CD will only list products that have been posted within the last six months. However, to ensure that all products are displayed, locate the Filter By section, and change the last drop-down menu (circled in Figure 2) to a value of "All". Finally, click the Search button beneath the Filter By section to continue.

Figure 2: Search By / Filter By screen

The results of your search will then be displayed as in Figure 3. To choose a program, put a checkmark in the checkbox to the left of a listing. Any dependencies for a product, such as the Bentley IEG License Service or Bentley Desktop Prerequisite Pack, will be listed below the product. You may leave a dependency unchecked if it is already installed. 

Figure 3: Search results screen

Once all needed products have been selected, click the Continue button at the bottom to proceed. Be sure to select the latest listing of a product by looking at the date and version columns since more than one version may be posted. More recent postings are near the top of the search results list.

The following screen, as shown in Figure 4, will list the products chosen on the previous screen. Any duplicates can be unchecked from here. Two delivery methods are listed below the selections list. By default, selected products are downloaded from Bentley's website, but the selected products can also be burned to CD and shipped to you by choosing the Burn CD option instead. Click the Continue button at the bottom to proceed.

Figure 4: Selection screen

The next screen displays legal terms. Please review these terms, and click the Accept button at the bottom to continue. If the download option was chosen on the previous screen, a download screen like the one in Figure 5 will be displayed. Internet Explorer users may optionally use the Advanced Download Manager to download selected products. Otherwise, the selected products can be downloaded by clicking the Download links to the right of each listing. Multiple products may be downloaded simultaneously by clicking the Download link for a second product once the first one has started downloading. If asked to run or save the file, choose to save the file, and save it to a location that is easy to get to such as your desktop.

Figure 5: Download screen

To install a product, double-click on one of the downloaded programs. The installation files for the product will be unpacked in a specified folder (by default C:\BentleyDownloads). For most products, the installer will start automatically after the files have been unpacked, however some updates, like Ram Elements 13.00.02.37 do not. in those cases the user should navigate to the extracted files location (C:\BentleyDownloads\re13000237en\RootFilesMoved) and run the msi file within (re_upgrade_130002_en.msi). A good thing to watch for is the End User License Agreement (EULA, or Legal agreement). If you never click accept to this then you have not actually installed the application.

Once all of your products have been installed, the BentleyDownloads folder may be deleted.

See Also

Product TechNotes and FAQs

Licensing TechNotes and FAQs

The technotes and FAQs in this section cover various topics that pertain to installing Ram Connection or using it the first time.

The technotes and FAQs in this section cover various topics that pertain to installing Ram Elements or using it the first time.

Problem Description

IMPORTANT- Ram Connection V8i release 09.02.00.117 was released on October 23, 2014 and that installer should be used if possible. The following content is ONLY for Non-SELECT users who have version 9.1.0.94.

Ram Connection builds are occasionally created to fix problems and disseminated via links on this page before full installers can be posted to My SELECT CD. This page is for Ram Connection in English or Spanish, but users should only download one or the other.

Solution

1. Install the latest release build of the software: Ram Connection 9.1.0.94 

2. Download the following file and save it to the hard drive. We suggest you save it in the same location as the main installer, (e.g. C:\BentleyDownloads).

3. Close Ram Connection, Ram Elements, and Ram Structural System if they are running.

4. Extract the files using to the following directories, 

IMPORTANT - use only 7-zip to extract these files, not Windows or WinZip. If 7-zip is not an option, then contact support with a service request. Otherwise the extracted files may have an altered time stamp and the upgrade will fail, giving an error like this:

Details about this unzipping time stamp problem here. 

* These are the default or typical paths for an English language operating system. For other language OS, or when the install path was changed from "Typical", the folder should match the path to the file RAMConnection.exe. On x32 bit machines eliminate the (x86) from the folder path. 

Overwrite existing copies in all cases:

Also merge the contents of any subfolders:

5. Confirm success by checking Help (?) - About for the updated release 9.1.0.101:

See Also

[[Ram Elements - Installing Updated Executables]] 

Structural Product TechNotes And FAQs

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Problem Description

After installing RAM Connection v9.0, the Connection toolbar and Conn tab in RAM Elements no longer appear.

Explanation

RAM Elements 13.00.03.47 and earlier does not support RAM Connection v9.0. RAM Connection for RAM Elements v8.0 must remain installed in order to use the connection module in those versions of RAM Elements. If RAM Elements for RAM Connection was uninstalled before installing RAM Connection v9.0, then the Connections toolbar and Conn tab will be removed.

Steps to Resolve

Option 1

1. Install Ram Elements 13.02.00.99 or later.

2. Make sure the License configuration within Ram Elements is set to "use a Ram Connection License in each session". See this article for details. 

Option 2

The following steps can be used to restore Ram Connection 8 functionality with Ram Elements 13.00.03.47 or earlier.

If RAM Connection v9.0 has not been installed, make sure that RAM Connection for RAM Elements is not uninstalled prior to running the installation setup.

If RAM Connection v9.0 has been installed and RAM Connection for RAM Elements was uninstalled, open the Setup.exe file in C:\Bentley Downloads\rc08000023en. If this file is not found, download the installation for RAM Connection v08.00.00.23 from the SELECT download page. Click here for instructions on accessing the download page.

In the setup dialog, click the link labeled "Install RAM Connection for RAM Elements" as shown in the screen capture below to reinstall the component.

See Also

[[RAM Connection is installed, but the Connection button fails to appear in RAM Elements]]

Why does RAM Elements also retrieve a RAM Connection license?

Product TechNotes and FAQs

Structural Product TechNotes And FAQs

The TechNotes and FAQs in this section cover various topics that pertain to RAM Connection. Use the navigation tree on the left to browse or the popular links below.

Installation and Licensing

• [[Ram Connection appears to install, but there is no shortcut created]]
• [[RAM Connection v9.0 and RAM Elements]]
• RAM Connection is installed, but the Connection button fails to appear in RAM Elements

Technical

• RAM Connection Capabilities and Modeling FAQ
• Troubleshooting Errors when Assigning Connections
• RAM Connection Stalls When Assigning Base Plate Connection
• Catastrophic Failure Error when Using Customized Anchor Position
• RAM Connection Extended End-Plate Moment Connections (MEP)
• RAM Connection Base Plate FAQ
• Tips for Using RAM Connection within STAAD.Pro [TN].
• How to Customize a RAM Connection Template in STAAD.Pro
• What Connection Types are available in RAM Connection to the design code BS 5950?

Problem Description

Running the rc09000041en.exe file appears to install quickly, but the installation is not complete. No shorcuts are created on the desktop or in the start menu and no files are put in c:\Program Files (x86)

Reason

The file rc09000041en.exe only extracts files and subfolders to some directory on the hard drive when it is run. The path to that folder is set in the second screen and defaults to C:\BentleyDownloads\rc09000041en

But this process is just the extraction of the file contents, not the actual installation of the software.

Steps to Resolve

1. Open the folder where the contents have been extracted, e.g. C:\BentleyDownloads\rc09000041en
2. Drill into the subfolder called "Install CD of RAMConnection 9.0" 
3. Run Setup.exe

See Also

[[Why does RAM Elements also retrieve a RAM Connection license?]]

[[RAM Connection v9.0 and Ram Elements]]

Unable to Satisfy All Prerequisites for RAM Connection Release 9.0

Structural Product TechNotes And FAQs

Modeling and Design of Trusses in RAM Structural System

 The modeling of trusses in RAM Structural System can be done easily, but there are some important design issues to consider. Below is an image of a truss modeled using long beams for the chords on two separate levels.

If the truss needs to have a pitched top chord, that can also be done by modeling a column at the apex (on the top chord level between nodes 3 and 8 in the figure below), then model the top chord using two beams rather than one and modify the elevation of the column top to create the slope.

The diagonal and vertical members of the truss are modeled as vertical braces using the add-special brace command with an offset distance consistently measured from one reference column. If the braces do not meet at a common work point multiple nodes will results in RAM Frame creating eccentricities or abnormal analysis results.

The resulting truss will, by default, have internal nodes that are disconnected from the rigid diaphragm in the RAM Frame analysis. The end nodes, however, will still be connected to a rigid diaphragm. The presence of this rigid diaphragm has the effect of inhibiting the natural deflections of the truss. The top chord will not compress and the bottom chord will not elongate. Consequently, the net vertical deflection of the truss and the axial forces in the chord beams will be unconservative. For this reason, it is recommended not to use a rigid diaphragm when analyzing a truss for gravity loads. Similarly, the semi-rigid diaphragm stiffness will adversely affect the chord forces, some "Flexible/None" is the best diaphragm setting. 

If the same model is to be used for lateral analysis, then a decision has to be made about which frames are effective in resisting the lateral loads. If there is a rigid diaphragm connected to other braced frames, excluding the trusses, then the model can be set up using rigid diaphragms on all levels, then manually disconnect the trusses from the rigid diaphragm using the assign - nodes - diaphragm connection command. If the truss is required to be part of the lateral force resisting system, consider only attaching a single node to the diaphragm. The axial force in the chords will change depending on which node is connected to the rigid diaphragm.

There are a few additional limitations to consider in the design of trusses. Since the chord is generally modeled as a single beam, the section size must remain constant over the length. Similarly, since the chords are beams, they are limited to web vertical applications using W shapes, channels or tubes. The unbraced length of the chords can be specified in RAM Frame - Steel mode, but the default method will assume the chords are braced in both axes at each panel point. It is not possible to assign an axial release to the bottom chord at the support which is generally the way a top chord bearing truss with gravity loads is detailed. since the top and bottom chords are modeled on two separate levels they cannot converge to a point, there must always be at least a small separation between the chords.

See Also

Structural Product TechNotes And FAQs

RAM SS Semirigid Diaphragms

RAM Instability In Finite Element Analysis

What is the Working directory?

A RAM Structural System model file (e.g. filename.rss) is literally a WinZip file and within any .rss file you should find many component files of the same name with a wide range of extensions including (but not limited to) .b3d, .ram and .uid. These files are extracted from the model file and put into the working directory when opened in RAM Manager (in older versions of the program all of these files were simply saved together in the model directory).

For this reason the working directory should always be on the local drive and in a place in which the “user” has administrative rights. It’s also important for the user to have the rights to add, modify and delete files in the model directory.

Note: the working directory is set the first time the program is run, to confirm or edit the working directory location go to C:\ProgramData\Bentley\Engineering\RAM Structural System and double click the Ramis.ini file (c:\windows\ramis.ini prior to version 14). This should bring up the Ramis.ini file in Notepad (or other text editor). Look for the line that begins

working=path to working directory.

You can edit this path to the working directory here. Spaces are allowed as are references to mapped drives, but for the reasons mentioned above, a local drive should be used.

Also in the [Directories} section you will find the paths for other installation directories like the Tables folder where the program looks for all the tables and the default reports directory for saved reports.

For more information on the contents of the Ramis.ini file, refer to the RAM Defaults Guide [TN] . 

Are RAM Structural System models backwards compatible?

Regretfully Ram SS models are not backward compatible. Typically with each major release there are changes in the model data base format. Once models are converted to the new version they can no longer be used in prior versions.

When a model is converted a backup of the original file is automatically created in case there is any need to revert to the prior version.

Note, though version 14.06.01 is generally considered a minor release, file conversion from version 14.06.00 is required. See the 14.06.01 Release Notes for details.

When I open a model I get a warning, “This file appears to be currently opened by: User Name…”.

If the listed user really is in the file, they need to exit the program normally to release the model so that you can open it (RAM SS models do not allow for concurrent use).

If that user is not currently in the file or unavailable, you should navigate to the directory where the model is saved and look for a file of the same name with the file extension “.usr”. This is a lock file that was created when the user last accessed the model. The .usr file is normally deleted when the model is closed, but if the program terminated irregularly, the file might persist. Simply delete the .usr file and the .rss file can then be opened.

When I open a model I get a warning, “A temporary backup file has been found for this database (path to file), which indicates that the program abnormally terminated…”. 

If you select the “Most Recent Database” you are telling the program to reload the files from the working directory which should be the same as they were just before the crash. In such cases, we suggest that you immediately use the file – save-as feature to turn this into a new model file.

Clicking “Backup Database” deletes the working files and restores the files from the saved model whenever it was last saved. “Cancel” leaves everything alone. If your not sure when the last save occurred, click cancel and then check the modified date of the model file through an explorer window before returning to pick either option.

Starting with version 14.06 an additional backup file is created for models that crash and are then re-opened. A copy of the rss file with the extension .ssr is created if you reopen a model that is already expanded to the working directory indicating a previous crash or incomplete closure. Like the .backup file, the .ssr file can be renamed with a .rss extension to restore that version of the file.

When I open a model I get a warning, “Could not delete RAM model: filename. Working files in directory \path to working directory\, please use the explorer to delete these files.”

There are two situations where this message might appear. The first is a restriction to the working directory or the model directory. The user needs to have the rights to add, modify and delete files from both locations (preferably administrative rights). See above for more on the working directory.

The second problem is a corrupt or partial model file. If the model file is missing any of the critical component files it will not open correctly and the same message will appear. To investigate, rename the model file, changing the extension form .rss to .zip and double-click it to see what inside. You should see a series of files all with the same name but with a wide range of extensions including (but not limited to) .b3d, .ram and .uid. When a model file does not contain a complete set of component files it is unusable. It is a mystery what causes a file to become this way, but it seems that something must have interrupted the save process. A virus scanner may also be responsible.

At this point the backup file should be used, see below.

When attempting to load a module, I receive a message that a file with a db.sdf extension already exists.

The error may be caused by an installation issue with a database component included with RAM Structural System. Removing and reinstalling the component may resolve the issue. To do this, perform the following steps:

1. Open the Control Panel from the Windows Start menu (Windows XP/Vista/7) or Windows Start screen (Windows 8).
2. Open Add or Remove Programs (Windows XP) or Programs and Features (Windows Vista/7/8).
3. If running RAM Structural System 14.06.00 or earlier, remove Microsoft SQL Server 2005 Compact Edition. If running RAM Structural System 14.06.01 or later, remove either Microsoft SQL Server Compact 4.0 or Microsoft SQL Server Compact 4.0 (x64).
4. Locate and open the RAM Structural System installer (e.g. ramm14060100en.exe or ram6414060100en.exe), often stored in the Downloads folder.
5. Click the Install button next to Microsoft SQL Server Compact Edition, and proceed through the installation to restore the component.

See also [[Unable to find the requested .NET framework data provider]]

Something is wrong with my model file, is there an automatic backup?

Yes, in the directory where the model file is saved, there should be another file of the same name with the extension, “.backup”. Rename this file something.rss (you won’t be able to use the same name of the original model file unless you move or rename it first). The backup file should be a complete version of the model from the previous time it was saved. If your not sure when that was, simply check the modified date.

Note: when backing up your own files, it is only the .rss model file that you need to save. When restoring backup files or old files from a backup CD or tape, make sure the files are not read-only. If you attempt to open a RAM model that is read-only, you will get another warning, “Failed CopyRssFileToWorkingDir:…”, “Failed DeleteRssInWorkingDir:…”, or “File error 2,6”.

How can I reduce the size of my files?

A RAM Structural System model (file.rss) is already a compressed zip file, but the size of that file can become quite large, especially when the analysis and design results are saved with the file. In RAM Manager under the File menu is an option to ZIP the model. When zipping models using that command you will have the opportunity to purge the model of some unnecessary results (which can be regenerated later just by running the file again). The optional results are:

• Include the RAM Frame Wall Forces results
• Include other RAM Frame Analysis results
• Include RAM Concrete Analysis results
• Include the RAM Concrete Column Interaction Surfaces
• Include the RAM Concrete Shear Wall results.

See Also

[[Unable to find the requested .NET framework data provider]]

RAM Defaults Guide [TN]

RAM Table Editing [FAQ]

Product TechNotes and FAQs

Structural Product TechNotes And FAQs

Error or Warning Message

After creating a new model, the following error occurs when attempting to open RAM Modeler:

"Unable to find the requested .NET framework data provider. It may not be installed."

If the error is ignored and the Modeler is launched, another error will appear indicating a problem with the working directory copy of the file with the .db.sdf extension.

Reason

A dependency named Microsoft SQL Server Compact Edition is not installed properly.

Solution

Microsoft SQL Server Compact Edition is not installed correctly. Please perform the following steps:

1. Uninstall it from the Add or Remove Programs (Windows XP) or Programs and Features (Windows Vista/7/8) control panel.
   If running RAM Structural System 14.06.xx or later: Remove either Microsoft SQL Server Compact 4.0 or Microsoft SQL Server Compact 4.0 x64.
   If running RAM Structural System 14.05.xx or earlier: Remove Microsoft SQL Server 2005 Compact Edition.
2. Reinstall the component.
   If running RAM Structural System 14.03.xx or later: Open the RAM Structural System installer (e.g. rss14030000en.exe or ramm14050300en.exe), and click the Install button next to Microsoft SQL Server Compact Edition.
   If running RAM Structural System 14.02.xx or earlier: Run SQLServerCE31-EN.msi located in RAM Structural System\Prog.

See Also

[[SELECTsupport TechNotes And FAQs]]

How is the Building and Frame story shear calculated?

When the program calculates the shear at a particular level, it does so by adding up all of the horizontal components parallel to the global X and Y axes for all of the lateral columns, braces and walls at the given story.

Total Story Shear is calculated based on all of the nodes at a level.

Diaphragm Story Shear is calculated based on the subset of the story nodes and members within a specific diaphragm boundary. The total shear at nodes that are disconnected from the diaphragm or outside a diaphragm boundary are reported as Diaphragm # "None" at each level in the Building Story Shear Report.

Frame Story Shear is a subset of the story nodes and members associated with a specific frame number. 

Why does the Frame story shear suddenly change at one level?

Multi-story Braces

When a brace is modeled such that it bypasses a level, it will not have any nodes at that intermediate level. Thus, when the program sums all of the loads for that level, the forces within those braces are not accounted for. The net force given in the report is therefore low, and the change in shear may appear as negative.

As you can see, the story shear is correctly reported for the Roof level and the 2nd level where the braces have nodes. At the mezz. Level, however, the braces have no nodes, so the forces within those braces are not included. The only shear in the frame in that case is the shear in the columns, which in this case is null. So the total shear that the program recognizes at the mezzanine level is 0, which is a loss of 24k from the level above.

Obviously, this information is not helpful. In those cases, it is recommended that you strike out the intermediate levels from the frame story shear report altogether, and recalculate the "change in shear" value manually.

Inconsistent Frame Numbering

A common cause for unexpected frame story shear results is inconsistent frame numbering. For example, if you delete and remodel the braces in the modeler, the new braces are automatically assigned Frame #0. If you do this at one level but not another level and forget to reassign the frame numbers to the new braces then the frame story shear will be confusing.

Generally speaking the best policy is to assign the frame columns and braces of any interconnected frame a single number. Corner or L shaped frame may be an exception to this rule as described on the RAMSS Pseudo Flexible Diaphragms FAQ.

Upper level Foundation nodes

If there is a base node above the very base level of the model, then here will be a reaction at that foundation node and the total shear in the frame below this point will not count the upper reaction.

Diaphragm Connections

In any structure, it's common to see the frame story shear changing and forces moving from one frame to another through the horizontal diaphragm, this can happen whether the diaphragm is rigid or semi-rigid or even in flexible diaphragm situations if there are lateral members tying the various frames together. For a more complete explanation see RAM SS - Rigid Diaphragm Constraints and Frame Shear [TN].

Through what point is the building story shear plotted?

To show the building story shear on screen use Process - Results - Building Story Shears. Display of building story shear - diaphragm shear is through the diaphragm center of mass. Where there is no diaphragm, or for shear associated with diaphragm "None", the plot is through the a somewhat arbitrary location near the geometric center of all framing.

See Also

Structural Product TechNotes And FAQs

RAM SS - Rigid Diaphragm Constraints and Frame Shear [TN]

Dynamic Story Shear

How does a dynamic analysis using response spectra for seismic loads differ from a static analysis using equivalent lateral forces?

Dynamic load cases are not story forces in the same sense as the static load cases. When a dynamic load case with a code selected or user-generated response spectrum is analyzed, the program finds the Eigen solution and determines the modal response for each of the modes included in the analysis. The modal response is based on the response spectra assigned to the dynamic load case, which defines the acceleration vs. period spectrum curve. The modal responses are then combined in some fashion to determine the total response of the structure.

How can I change the number of modes used in the dynamic analysis?

Create an Eigen solution dynamic load case and enter the number of modes to consider. The number of modes can be changed at any point by changing this load case in RAM Frame (Loads > Load cases).

How many modes should I consider?

Generally, building codes require that the dynamic analysis include a sufficient number of modes to obtain a combined modal mass participation of 90% of the total building mass in each of the two orthogonal directions (see ASCE 7-05 12.9.1). The mass participation can be found in the Period & Modes Report under the section titled “Modal Effective Mass Factors” The “%Mass” values represent the mass participation for one particular mode; the “%SumM” values represent the cumulative mass participation. The X and Y modes with the highest mass participation represent the fundamental modes; the program will use the period and frequency associated with these modes in the calculation of the static seismic and wind loads when these values are chosen to be calculated by the program.

There is not a fixed number of modes that need to be specified in order to obtain the 90% mass participation. Rigid diaphragms have 3 degrees of freedom for each diaphragm (x-translation, y-translation, and z-rotation). If you need to include more modes than 3*number of diaphragms to obtain 90% mass participation, then you may need to increase the stiffness or look for instabilities in the model.

Note that when semirigid or pseudo- flexible diaphragms are used, there are 2 mass degrees of freedom for each node (x-translation and y-translation). As a result, default number of modes used by the program may be very large when no Eigen solution dynamic load case is created. In such cases, the number of modes can be changed as noted above.

When I look at the Period & Modes Report, I see that the cumulative mass participation for rotation is always 0% no matter how many modes are included in the analysis?

If a diaphragm includes a two-way deck or it is defined as a semirigid diaphragm, it is meshed and represented with finite (shell) elements. Each node of the finite elements has a nodal (point) mass associated with it. In other words, the diaphragm mass is represented with a network of spatially distributed nodal masses. Note each node includes point mass defined in the global X and Y-directions but not include rotational mass moment of inertia. Because the array of masses does not include rotation, the mass participation for this degree of freedom will always be 0. For the same reason, the mass participation for the rotational degree of freedom will also be 0 when pseudo-flexible diaphragms are used.

It should be known that this type of modeling still suffices for capturing all essential dynamic properties. In other words, the proposed solution accurately captures any dynamic actions related to rotational inertias or any twisting modes due to having center of rigidity and mass center at different locations.

What scale factor should I apply to the response spectrum?

The response spectrum analysis should be factored by the quantity I/R for both forces and drifts. Some codes require the dynamic forces (but not drifts) to be scaled so that the dynamic base shear is at least a specified percentage of the base shear calculated from the equivalent lateral force procedure (see ASCE 7-05 12.9.4, for example). The total base shear is reported in the Building Story Shear Report (Report > Building Story Shear). When the ground level is set to a level other than the base of the model, it is best to use the value reported for the level immediately above the specified ground level.

If you are not considering sign in the analysis, then the perpendicular dynamic base shear value is not really relevant to the X direction scale factor (it could be a result of torsion on the structure only), so we usually recommend scaling the Dynamic load based on the base shear parallel to the load angle.

Should I use SRSS or CQC modal combination?

The CQC method is recommended as the SRSS method can give inaccurate results for 3D structures. When 2D structures are analyzed, the methods will produce similar results.

Does the dynamic analysis consider accidental torsion?

Most building codes require the inclusion of accidental torsion for both the equivalent static load procedure and dynamic analysis. The code requirements for evaluating accidental torsion for dynamic load cases are implemented in RAM Frame when rigid diaphragms are used. To include eccentricity, set the eccentricity to “+ and –" for the x and y directions in the Response Spectra dialog when the dynamic load case is created. The % eccentricity is defined in the Mass dialog in RAM Frame (Loads > Masses). It should be noted that accidental torsion effects can be included in analysis for only rigid diaphragms. For pseudo-flexible diaphragm, it is assumed that a flexible diaphragm is not able transmit diaphragm torsional moments, and hence accidental torsion effect is ignored for flexible diaphragms. In RAM Structural System v14.0.4, accidental torsional effects are also not considered for semirigid diaphragms. These effects are included in v14.2.2.

Why do the analysis results for all members in the model have positive values?

The modal response (nodal deflections, member forces, reactions) determined from a response spectra analysis have signs associated with them. However, once the analysis results are determined by combining the modal results using either the SRSS or CQC method, each response has only a positive value. Because the sign of the result is important for member design, there is an option in the RAM Frame (General > Criteria) to consider the sign in the results. When this option is selected, the sign of the analysis result will match the sign from the predominant modal result. You should not design continuous footings, gusset plate connections, or other elements based on the forces from multiple members using dynamic results unless the sign of the analysis result has been considered.

Why don’t the values reported for the building story shear correspond to the values reported for the change in story shear?

The combination of modal results can affect interpretation of the results, especially building story shear and change in story shear. The program calculates a total story shear and a change in shear for each mode in the analysis. The results are each combined using either the SRSS or CQC combination. As a result, the reported change in shear is not linearly related to the reported building shear. For the same reason, the reported building story shears should not be expected to match the sum of the reported frame story shears. If one is trying to determine equivalent static forces to apply to the diaphragms to match the total base shear, the reported shear from one level should be manually subtracted from the shear reported in the adjacent level rather than using the change in shear values reported in the Building Story Shear Report.

How do I generate load combinations with dynamic loads cases?

Dynamic loads cases are included in the default load combination installed with the program. This was a feature enhancement in v14.05.03. See following web page for release notes: RAM SS v14.05.03 Release Notes

In previous versions of programs, dynamic load cases were not included in the load combination templates. In these versions, you can create load combinations with dynamic load cases using the custom load combinations dialog. You may find it helpful to first generate load combinations with the templates using equivalent lateral force seismic load cases (E) and then modify the load combinations to use the dynamic load case (Dyn) by changing E to Dyn. You can also copy and paste load combinations from another load combination dialog or text document into the custom load combination dialog or create a custom load combination template to include the dynamic load cases.

How can I account for 100/30 orthogonal load effects when using dynamic load cases?

Experts have recommended using a SRSS combination of two orthogonal response spectra analyses to determine the critical forces in a dynamic analysis (see reference below). This method is not implemented in the current version of RAM Structural System. You will need to use load combinations to account for this code requirement.

“A Clarification of the Orthogonal Effects in a Three-Dimensional Seismic Analysis,” E.L. Wilson, I. Suharwardy, and A. Habibullah, EERI Earthquake Spectra, Vol. 11, No. 4, Nov. 1995.

I ran my model with a Response Spectrum analysis using a custom .rsp file, but the results are all zero, what's wrong?

The program interpolates acceleration values from the user provided table, but it does not extrapolate acceleration values past the last data point. It's critical that the last period value in the table is longer than the first mode shape to get accurate results.

For further details see the Ram manager manual section titled, "RAM Frame Response Spectra Tables".

See Also

Product TechNotes and FAQs

Structural Product TechNotes And FAQs

RAMSS Eigenvalue Error

STAAD.Pro Response Spectrum FAQ

The TechNotes and FAQs in this section cover various licensing and installation related topics that pertain to RAM, STAAD, or other Structural Analysis and Design applications. Use the navigation tree to the left to browse topics. Some of the most popular topics are also listed below.

• Configuring Structural Products For SELECT Server
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• [[Non-Interactive Installation Of Structural Products]]
• [[Performing A Clean Installation]]
• [[Structural Products Licensing FAQ]]
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• Why do RAM Structural System modules open in trial mode?
• Why is a license for my RAM or STAAD product missing from the License Checkout list?

Hello,

I was serching this forum for similar subject and unfortunately can't find anything similar.

I need to model steel construction build of standard components like: Angles, Channels, Rectangular Hollow Sections etc.

I would like to make all these components (Angles, Channels, RHS etc.) as feature cells which parameters I can modify if there is a need, or at least to have opportunity to choose them from the list created via Parameter Set.

When I draw something simple like angle or channel (shape) without circular fillets everything works fine, I can go through the whole process of adding constraints, parameter lists,parameter set, eventually extrude profile and create proper feature cell which then I can edit or substitute with another with different parameters etc.

Here is the problem: when the angle or channel has circural fillets and becames complex shape, after adding all constraints the profile doesn't like to be extruded with feature tools. I was trying to make a group from it, in one case it did work but not to the very end, usually it does't work at all. I'm using old Microstation XM, but at home I was trying to do the same in the newest demo version and it still doesn't want to extrude profile with fillets after constraints are added to it.

Obviously when I create profile without constaints I can extrude it no problem, but then it doesn't have any parameters etc and this is what I'm after of course.

Do you know how to make Microstation add constraints to profile with circural fillets and make it parametric? Next step would be to create Rectangular Hollow Section which is hollow inside (both - section and hollow part have fillets, but I'm not at this stage yet).

Hope what I was written is clear. I do not know how to add screen grabs to the post to make it clearer unfortuantely.

Please advise, or send me to the proper place if you would be so kind. I'm absolutely new to parametric modeling but consider it as very powerfull way of working with Microsatation.

Many thanks AK

 ISM Revit Plug-in Best Practices 

 Change Story Level

See Also

Integrated Structural Modeling Home

Load History Parameters in RAM Concept

RAM Concept uses the ACI 209R-92 models for creep and shrinkage. In these models, only modifications that are a function of time are accounted for internally by the program. Other factors that affect creep and shrinkage rates are defined by the user in the Calc Options dialog (see Figure 1 below). The purpose of this tech note is to describe how these parameters are used in the load history calculations and discuss the default values.

More discussion on the theoretical basis for the load history deflection method used in RAM Concept can be found on the following web page:

Load History Article

Figure 1. Load History Parameters in Calc Options Dialog

Creep Factor

The creep factor is defined as the ratio of total strain (elastic strain + creep strain) to elastic strain. According to ACI 209, an average value creep strain:elastic strain is 2.35. As a result, RAM Concept adopts a default creep factor of 1 + 2.35 = 3.35. The ACI 209 average value and the RAM Concept default are based on standard conditions. Other factors, like curing method, concrete composition, and cement content, can affect creep and should be incorporated into the creep factor that is defined.

The ACI 209 creep model assumes that the initial loading is applied at 7 days. Some codes, like AS 3600, assume a
different time for initial load application. When using the load history calculations in RAM Concept, the creep factor should be converted for an initial loading time of 7 days.

ACI 209 defines a modification factor for initial load application times other than 7 days. This correction is automatically included in the load history calculations and should not be incorporated into the input creep value. The initial load application time defined in the Calc Options dialog is used to calculate this correction. This correction factor is automatically calculated and applied for each load history step and is based upon the time of application of loading in each step.

Shrinkage Strain

According to ACI 209, average shrinkage strains range from 0.000415 to 0.001070 for standard conditions. RAM Concept uses a default value of 0.0004.

Environmental factors, especially ambient relative humidity, can have a significant impact on the ultimate shrinkage strain and should be considered when inputting the value in the Calc Options dialog. If the relative humidity is low, the shrinkage value could be significantly higher than the default value.

ACI 209 defines a modification factor for shrinkage strain for conditions with a moist cure duration other than 7 days. RAM Concept uses the input Moist Cure Duration in the Calc options dialog to automatically account for this modification. Input shrinkage strains should not include this modification.

Shrinkage Restraint

Elements like stiff columns and walls restrain shrinkage movements and cause a gradual buildup of tensile stress in the concrete, which leads to cracking. The shrinkage restraint percentage is a simple way to account for this cracking. The higher the percentage the earlier cracking will occur and the more the tension stiffening effect will be reduced.

RAM Concept uses the shrinkage restraint percentage as follows:

The ACI 209 time function for shrinkage and the input ultimate shrinkage strain are used to calculate the shrinkage strain at each given time step. This shrinkage strain is multiplied by the defined shrinkage restraint percentage. This tension strain is then summed with the modified concrete strain determined in the load history calculations (accounting for creep, etc.) for use with the concrete stress-strain curve to find the concrete stress.

Here is a simplified numerical example, illustrating the effect of the shrinkage restraint percentage:

User input shrinkage strain = 0.0004

User input shrinkage restraint = 10%

Elastic Modulus of Concrete = 3605 ksi

Assuming the concrete is linear elastic, the stress increase due to the shrinkage restraint would be (3605ksi)*(0.0004)*(0.1) = 0.144 ksi. This is roughly 1/3 of the cracking stress. In other words, the shrinkage restraint is reducing the cracking moment by about 1/3.

From a practical standpoint, setting the restraint percentage to 30% would reduce the cracking moment to zero (in the
absence of axial compression), cause all elements on the floor to crack, and significantly increase deflections. Increasing the value above 30% would have very little effect, since it would not affect cracking and would only reduce the tension stiffening effect slightly.

The following are some recommendations for the user input shrinkage restraint assuming an ultimate shrinkage strain of 0.0004 (use engineering judgment for interpolations between):

0% - unrestrained or very lightly restrained slabs (flexible columns only, single stiff element)

10% - normally restrained slabs (more than one stiff element, some flexibility)

20% - completely restrained slabs (basement walls around entire perimeter, etc. causing a high degree of
restraint)

For other values of shrinkage strain, the percentages can be calculated based on an appropriate reduction to the cracking moment using the simple numerical example above. For example, for a given shrinkage strain and a desired reduction in cracking moment of 33%, the user input shrinkage restraint would be calculate from fr*0.33/(E*n)

Where,

fr = modulus of rupture

E = Elastic Modulus of Concrete

n = shrinkage strain

Ageing Coefficient

The ageing coefficient accounts for the rate of application loading for the calculation of creep effects. The RAM Concept Manual describes this parameter as follows:

“An ageing coefficient is used as a modifier of creep to account for the rate of application loading, its effect on the creep and the variation of concrete strength over the time period. While the rigorous calculation of the coefficient is rather involved, this value can normally be taken as 0.8 with little loss in accuracy.”

See Also

Load History Article

Ram Concept - Load History Convergence

RAM Concept Load History Deflections and ACI Deflection Limits

Structural Product TechNotes And FAQs

For my requirement , i tried for natural frequency analysis of a cantilever beam.

While analysis the model its generates the warning message, " Instability at Joint" , How does it can be rectified?

Pls. find the below the model.  I would appreciate any assistance anyone could give me with this. 

STAAD SPACE
START JOB INFORMATION
ENGINEER DATE 09-Sep-14
END JOB INFORMATION
INPUT WIDTH 79
UNIT METER KN
JOINT COORDINATES
1 0 0 0; 2 0 0.04 0; 3 0 22 0; 4 0 11.02 0; 5 0 16.51 0; 6 0 5.53 0;
7 0 19.255 0; 8 0 13.765 0; 9 0 8.275 0; 10 0 2.785 0; 11 0 1.4125 0;
12 0 4.1575 0; 13 0 6.9025 0; 14 0 9.6475 0; 15 0 12.3925 0; 16 0 15.1375 0;
17 0 17.8825 0; 18 0 20.6275 0; 19 0 21.3138 0; 20 0 19.9412 0; 21 0 18.5687 0;
22 0 17.1963 0; 23 0 15.8237 0; 24 0 14.4513 0; 25 0 13.0788 0; 26 0 11.7063 0;
27 0 10.3337 0; 28 0 8.96125 0; 29 0 7.58875 0; 30 0 6.21625 0; 31 0 4.84375 0;
32 0 3.47125 0; 33 0 2.09875 0; 34 0 0.72625 0; 35 0 0.02 0; 36 0 0.03 0;
37 0 0.01 0;
MEMBER INCIDENCES
1 1 37; 2 2 34; 3 4 26; 4 5 22; 5 6 30; 6 7 20; 7 8 24; 8 9 28; 9 10 32;
10 11 33; 11 12 31; 12 13 29; 13 14 27; 14 15 25; 15 16 23; 16 17 21; 17 18 19;
18 19 3; 19 20 18; 20 21 7; 21 22 17; 22 23 5; 23 24 16; 24 25 8; 25 26 15;
26 27 4; 27 28 14; 28 29 9; 29 30 13; 30 31 6; 31 32 12; 32 33 10; 33 34 11;
34 35 36; 35 36 2; 36 37 35;
DEFINE MATERIAL START
ISOTROPIC STEEL1
E 2.05e+008
POISSON 0.3
DENSITY 325.3
ALPHA 1.2e-005
DAMP 0.03
ISOTROPIC STEEL
E 2.05e+008
POISSON 0.3
DENSITY 76.8195
ALPHA 1.2e-005
DAMP 0.03
END DEFINE MATERIAL
MEMBER PROPERTY AMERICAN
2 TO 33 PRIS AX 0.56 AZ 0.56 IX 1.30415 IY 1.30415 IZ 1.30415
1 34 TO 36 PRIS AX 14.75 AZ 14.75 IX 17.32 IY 17.32 IZ 17.32
CONSTANTS
MATERIAL STEEL1 MEMB 2 TO 33
MATERIAL STEEL MEMB 1 34 TO 36
SUPPORTS
3 FIXED
CUT OFF MODE SHAPE 20
CUT OFF FREQUENCY 10000
LOAD 1
SELFWEIGHT X -1
SELFWEIGHT Y -1
SELFWEIGHT Z -1
MODAL CALCULATION REQUESTED
PERFORM ANALYSIS
PERFORM ANALYSIS PRINT MODE SHAPES
FINISH

Why are some tendons shown at the wrong elevation in the tendon perspective?

The soffit elevation at each profile point is determined during the Analyze All and Calculate All commands. If one of these commands is not performed since the drawing (or moving, etc.) of a tendon, or since a change in the mesh, the tendon elevations in perspectives are not accurate.

The same is true for elevations optionally shown as text on the plans.

It is quicker to analyze (but not using “Calculate All”) with Process > Analyze All. This avoids processing the design calculations.

How can I place a manual tendon relative to the top surface, rather than up from the soffit?

If you use manual tendons, they can be placed with an elevation relative to either surface or soffit. If you use the "Above soffit" approach and enter say 6.25” for the high points, then high points will stay 6.25” up from the soffit even if the slab thickness changes.

On the other hand, if you use the “Top cover” option with a small positive cover (or if you use the “Above surface” option with a small negative number), then the top of the strand will maintain the distance from the top surface and increasing the slab thickness will result in tendons with more drape.

What do the terms “Latitude” and “Longitude” mean?

In the USA, Britain and other countries it is typical practice to place all the tendons in one direction in a concentrated band over column lines. If the designer is using another practice then we recommend that you still use the Latitude and Longitude tendon layers because it makes editing the PT easier. i.e. Put the tendons in the X direction on one layer and the Y tendons on the other. Latitude and Longitude are just layer names.

Do I have to draw the tendons for a post-tensioned slab?

Yes. It is not difficult, and encourages you to address detailing issues before they become field problems.

How do I draw tendons?

See Chapter 26 Defining Tendons for details. It's important to note that the program allows you to manually define tendons on the manual tendon layers, or you can generate tendons based on user defined tendon parameters.

Can I harp tendons?

Yes. Any tendon segment can be declared to be harped. The “half-span” tendon tool is useful for any harp point (or any low point) that is not at mid-span. Multiple harp points can be located in any span by using multiple tendon segments.

Does it matter which way I draw “half” tendons?

Yes. The inflection point is measured from the first point clicked and the profiles are specified in the order of the points clicked. To be compatible with the tendons created using the Full Span Tendon tool, we strongly recommend that you always start at the high point.

Can I terminate some strands past a column?

This can be done with one of two methods.

The tendon can be “forked” such that the number of strands decreases. As shown in Figure 37-1, if the transition is from 15S (15 strands) to 10S (because an adjacent span does not require that many strands) then terminate 5S using a half span tendon. It is common to terminate strands at quarter span and at the slab centroid.

Note: You should only use this method for tendons with no jacks attached. This is because a jack attached to tendons of different lengths has inaccurate seating (wedge draw-in) loss calculations.

Figure 37-1 Termination of strands (no jacks)

The second method can be used when jacks are modeled. If the total number of strands is 15S then one tendon with 10S needs to be continuous with an additional tendon with 5S alongside. It is common to terminate tendons at quarter span and at the slab centroid.

Figure 37-2 Termination of strands / tendons (jacked). Plan alignment of tendons is subjective.

Does Concept check to make sure the number of strands in connected tendon segments is consistent?

Yes. you will get a warning to that effect during the calculation when the strand number changes.

How does Concept calculate friction losses?

Concept only calculates friction losses if jacks are specified. Concept performs friction loss calculations considering the (elevation view) curvature of the tendons, the (plan view) horizontal kinks in the tendon and the jacking and friction parameters. The stress in the tendon is assumed to vary linearly along each tendon segment.

Does Concept calculate elongations (extensions)?

Yes, if jacks are specified. Use the Visible Objects dialog to view "Jack Elongation" on the manual tendon standard plans.

Do the elongations (extensions) include the effect of the seating distance (wedge draw-in)?

Yes. The elongation reported includes the deduction of the seating distance.

Why do I get the warning:  "An error has been found.   A non-external tendon is out of a cross section in design strip x-x" 

RAM Concept is checking one of the design sections in that design strip. The particular section has been trimmed. It may have been trimmed due to the cross section trimming method (e.g. using Max rectangle trimming could trim off any beams or drop panels in the section) or because of the slope limit which prevents adjacent sections from rapidly jumping in depth. Where there error occurs, there is a tendon passing through this section within the part of the section that was trimmed off.

To fix the problem either revise the strip trimming methods and/or verify the cross section in perspective view. You may need to revise the design strips in plan or move the tendon in some cases.

Can Ram Concept identify tendon clashes?

Our 3D graphics for tendons are very accurate and you can visually inspect them using tendon perspective plots, but we don’t call out or highlight clashes in Ram Concept.

See Also

[[RAM Concept Tendon Parameters]]

Cross Section Trimming

Product TechNotes and FAQs

Structural Product TechNotes And FAQs